U.S. patent number 11,374,686 [Application Number 17/166,993] was granted by the patent office on 2022-06-28 for parity check bits for non-coherent communication.
This patent grant is currently assigned to QUALCOMM Incorporated. The grantee listed for this patent is QUALCOMM Incorporated. Invention is credited to Wanshi Chen, Yi Huang, Hwan Joon Kwon, Hung Dinh Ly, Gokul Sridharan, Wei Yang.
United States Patent |
11,374,686 |
Yang , et al. |
June 28, 2022 |
Parity check bits for non-coherent communication
Abstract
A method of wireless communication at a transmitting device
includes adding parity check bits to a set of information bits. The
method also includes generating a non-coherent transmission signal
by mapping the parity check bits and the set of information bits
into a sequence of complex symbols. Further, the method may include
transmitting the non-coherent transmission signal to a receiving
device. A method of wireless communication at a receiving device
includes receiving, from a transmitting device, a non-coherent
signal having at least one segment. Each segment comprises a
sequence of complex symbols corresponding to information bits and
parity check bits. The method also includes jointly detecting the
sequences from each segment of the received non-coherent signal by
using the parity check bits.
Inventors: |
Yang; Wei (San Diego, CA),
Huang; Yi (San Diego, CA), Ly; Hung Dinh (San Diego,
CA), Sridharan; Gokul (Sunnyvale, CA), Kwon; Hwan
Joon (San Diego, CA), Chen; Wanshi (San Diego, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
QUALCOMM Incorporated |
San Diego |
CA |
US |
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Assignee: |
QUALCOMM Incorporated (San
Diego, CA)
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Family
ID: |
1000006398847 |
Appl.
No.: |
17/166,993 |
Filed: |
February 3, 2021 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20210242967 A1 |
Aug 5, 2021 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62970131 |
Feb 4, 2020 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L
1/0063 (20130101); H04B 7/0413 (20130101) |
Current International
Class: |
H04L
1/00 (20060101); H04B 7/0413 (20170101) |
References Cited
[Referenced By]
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Apr 2018 |
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EP |
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Feb 2018 |
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WO |
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WO-2018119153 |
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Jun 2018 |
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WO |
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WO-2018141212 |
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Aug 2018 |
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WO |
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WO-2018167980 |
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Sep 2018 |
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WO |
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WO-2019063534 |
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Apr 2019 |
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WO |
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Other References
International Search Report and Written
Opinion--PCT/US2021/016602--ISA/EPO--dated Apr. 28, 2021. cited by
applicant .
Skander C-D., et al., "Rate-Adaptive Transmission of H.263 Video
for Multicode DS/CDMA Cellular Systems in Multipath Fading", VTC
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(May 6, 2002), XP001210431, pp. 473-477,
DOI:10.1109/VTC.2082.1082768 ISBN: 978-0-7803-7484-3. cited by
applicant .
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CDMA Wireless Communications", VTC'98. 48th, IEEE Vehicular
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48, May 18, 1998 (May 18, 1998), XP000903354, pp. 1920-1924, ISBN
978-0-7803-4321-4. cited by applicant .
Samsung: "On Short PUCCH with 1 Symbol", 3GPP Draft, 3GPP TSG RAN
WG1 Meeting #88bis, R1-1705388 On Short PUCCH with 1
Symbol-Samsung, 3rd Generation Partnership Project (3GPP), Mobile
Competence Centre, 650, Route Des Lucioles, F-06921
Sophia-Antipolis Cedex, France, vol. RAN WG1, No. Spokane, USA,
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URL:http://www.3gpp.org/flp/Meetings_3GPP_SYNC/RAN1/Docs/[retrieved
on Apr. 2, 2017]. cited by applicant.
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Primary Examiner: Pham; Chi H
Assistant Examiner: Agureyev; Vladislav Y
Attorney, Agent or Firm: Seyfarth Shaw LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims the benefit of U.S. Provisional
Patent Application No. 62/970,131, filed on Feb. 4, 2020, and
entitled "PARITY CHECK BITS FOR NON-COHERENT COMMUNICATION," the
disclosure of which is expressly incorporated by reference in its
entirety.
Claims
What is claimed is:
1. A method of wireless communication at a transmitting device,
comprising: adding parity check bits to a set of information bits;
segmenting the set of information bits and the parity check bits
into a plurality of segments comprising subsets of information plus
parity bits, the segmenting occurring after the adding; generating
a non-coherent transmission signal by mapping the subsets of
information plus parity bits into a plurality of sequences of
complex symbols; and transmitting the non-coherent transmission
signal to a receiving device.
2. The method of claim 1, in which the parity check bits comprise
cyclic redundancy check (CRC) bits.
3. The method of claim 2, in which the parity check bits further
comprise additional parity check bits based on the set of
information bits and/or the CRC bits.
4. The method of claim 1, in which generating the non-coherent
transmission signal comprises: mapping each subset to a respective
sequence of the plurality of sequences for the non-coherent
transmission signal, each sequence comprising n complex
symbols.
5. The method of claim 4, in which the parity check bits comprise
cyclic redundancy check (CRC) bits and additional parity check bits
that are based on at least two different subsets of the set of
information plus parity bits and/or at least two different subsets
of the CRC bits.
6. The method of claim 4, in which the plurality of sequences are
concatenated to form the sequence of complex symbols for the
non-coherent transmission signal.
7. The method of claim 4, in which the plurality of sequences are
super-positioned to form the sequence of complex symbols for the
non-coherent transmission signal.
8. The method of claim 4, further comprising determining a quantity
of the plurality of segments based on a quantity of bits for a
payload, in response to the set of information bits comprising the
payload.
9. The method of claim 1, in which the information bits comprise an
uplink control information (UCI) payload transmitted on a physical
uplink control channel (PUCCH).
10. The method of claim 1, in which the parity check bits comprise
a first quantity of cyclic redundancy check (CRC) bits when a
payload corresponding to the set of information bits is smaller
than a threshold and the parity check bits comprise a second
quantity of bits when the payload corresponding to the set of
information bits is greater than the threshold.
11. The method of claim 1, in which the parity check bits comprise
a first quantity of cyclic redundancy check (CRC) bits and a second
quantity of additional parity check bits when a payload
corresponding to the set of information bits is smaller than a
threshold, and the parity check bits comprise a third quantity of
CRC bits and a fourth quantity of additional parity check bits when
the payload corresponding to the set of information bits is greater
than the threshold.
12. The method of claim 1, further comprising determining a
quantity of parity check bits based on a quantity of segments into
which the set of information bits are partitioned.
13. A method of wireless communication at a receiving device,
comprising: receiving; from a transmitting device; a non-coherent
signal having a plurality of segments, each segment comprising a
sequence of complex symbols corresponding to a subset of
information bits and a subset of parity check bits; and jointly
detecting the sequence from each segment of the received
non-coherent signal by using the parity check bits.
14. The method of claim 13, in which the jointly detecting
comprises: generating a list of candidates for each sequence; and
finding the sequence in each list of candidates based on the parity
check bits.
15. The method of claim 14, in which finding the sequence further
comprises finding the sequence such that corresponding information
bits and parity check bits of the sequence in each list of
candidates satisfy parity check conditions represented by the
parity check bits.
16. The method of claim 15, in which a product of a size of each
list is smaller than a threshold that is based on a predetermined
false alarm rate and a quantity of parity check bits.
17. The method of claim 13, further comprising determining a
quantity of parity check bits based on a quantity of bits for a
payload in response to the information bits comprising the
payload.
18. The method of claim 13, further comprising determining a
quantity of the plurality of segments based on a quantity of bits
for a payload in response to the information bits comprising the
payload.
19. The method of claim 13, further comprising determining the
information bits based on jointly detecting the sequence from each
segment.
20. A transmitting device for wireless communication comprising: a
memory, and one or more processors operatively coupled to the
memory, the memory and the one or more processors configured: to
add parity check bits to a set of information bits; to segment the
set of information bits and the parity check bits into a plurality
of segments comprising subsets of information plus parity bits, the
segmenting occurring after the adding; to generate a non-coherent
transmission signal by mapping the subsets of information plus
parity bits into a plurality of sequences of complex symbols; and
to transmit the non-coherent transmission signal to a receiving
device.
21. The transmitting device of claim 20, in which the parity check
bits comprise cyclic redundancy check (CRC) bits.
22. The transmitting device of claim 21, in which the parity check
bits further comprise additional parity check bits based on the set
of information bits and/or the CRC bits.
23. The transmitting device of claim 20, in which the one or more
processors are further configured: to map each subset to a
respective sequence of the plurality of sequences for the
non-coherent transmission signal, each sequence comprising n
complex symbols.
24. The transmitting device of claim 23, in which the parity check
bits comprise cyclic redundancy check (CRC) bits and additional
parity check bits that are based on at least two different subsets
of the set of information plus parity bits and/or at least two
different subsets of the CRC bits.
25. The transmitting device of claim 23, in which the plurality of
sequences are concatenated to form the sequence of complex symbols
to form the non-coherent transmission signal.
26. The transmitting device of claim 23, in which the plurality of
sequences are super-positioned to form the sequence of complex
symbols to form the non-coherent transmission signal.
27. The transmitting device of claim 20, in which the parity check
bits comprise a first quantity of cyclic redundancy check (CRC)
bits when a payload corresponding to the set of information bits is
smaller than a threshold and the parity check bits comprise a
second quantity of bits when the payload corresponding to the set
of information bits is greater than the threshold.
28. The transmitting device of claim 20, in which the parity check
bits comprise a first quantity of cyclic redundancy check (CRC)
bits and a second quantity of additional parity check bits when a
payload corresponding to the set of information bits is smaller
than a threshold, and the parity check bits comprise a third
quantity of CRC bits and a fourth quantity of additional parity
check bits when the payload corresponding to the set of information
bits is greater than the threshold.
29. The transmitting device of claim 20, in which the one or more
processors are further configured to determine a quantity of parity
check bits based on a quantity of segments into which the set of
information bits are partitioned.
30. A receiving device for wireless communication comprising: a
memory, and one or more processors operatively coupled to the
memory, the memory and the one or more processors configured: to
receive, from a transmitting device, a non-coherent signal having a
plurality of segments, each segment comprising a sequence of
complex symbols corresponding to a subset of information bits and a
subset of parity check bits; and to jointly detect the sequences
from each segment of the received non-coherent signal by using the
parity check bits.
Description
BACKGROUND
Technical Field
The present disclosure relates generally to communication systems,
and more particularly, to non-coherent wireless communication.
Introduction
Wireless communication systems are widely deployed to provide
various telecommunication services such as telephony, video, data,
messaging, and broadcasts. Typical wireless communication systems
may employ multiple-access technologies capable of supporting
communication with multiple users by sharing available system
resources. Examples of such multiple-access technologies include
code division multiple access (CDMA) systems, time division
multiple access (TDMA) systems, frequency division multiple access
(FDMA) systems, orthogonal frequency division multiple access
(OFDMA) systems, single-carrier frequency division multiple access
(SC-FDMA) systems, and time division synchronous code division
multiple access (TD-SCDMA) systems.
These multiple access technologies have been adopted in various
telecommunication standards to provide a common protocol that
enables different wireless devices to communicate on a municipal,
national, regional, and even global level. An example
telecommunication standard is 5G New Radio (NR). 5G NR is part of a
continuous mobile broadband evolution promulgated by Third
Generation Partnership Project (3GPP) to meet new requirements
associated with latency, reliability, security, scalability (e.g.,
with Internet of Things (IoT)), and other requirements. 5G NR
includes services associated with enhanced mobile broadband (eMBB),
massive machine type communications (mMTC), and ultra reliable low
latency communications (URLLC). Some aspects of 5G NR may be based
on the 4G Long Term Evolution (LTE) standard. There exists a need
for further improvements in 5G NR technology. These improvements
may also be applicable to other multi-access technologies and the
telecommunication standards that employ these technologies.
SUMMARY
The following presents a simplified summary of one or more aspects
in order to provide a basic understanding of such aspects. This
summary is not an extensive overview of all contemplated aspects,
and is intended to neither identify key or critical elements of all
aspects nor delineate the scope of any or all aspects. Its sole
purpose is to present some concepts of one or more aspects in a
simplified form as a prelude to the more detailed description that
is presented later.
In some aspects of the present disclosure, a method of wireless
communication at a transmitting device may include adding parity
check bits to a set of information bits. The method may also
include generating a non-coherent transmission signal by mapping
the parity check bits and the set of information bits into a
sequence of complex symbols. Further, the method may include
transmitting the non-coherent transmission signal to a receiving
device.
In some aspects, a method of wireless communication at a receiving
device includes receiving, from a transmitting device, a
non-coherent signal having at least one segment. Each segment
includes a sequence of complex symbols corresponding to information
bits and parity check bits. The method may also include jointly
detecting the sequences from each segment of the received
non-coherent signal by using the parity check bits.
A transmitting device for wireless communication may include a
memory and one or more processors operatively coupled to the
memory. The memory and the one or more processors may add parity
check bits to a set of information bits. The transmitting device
may also generate a non-coherent transmission signal by mapping the
parity check bits and the set of information bits into a sequence
of complex symbols. The transmitting device may also transmit the
non-coherent transmission signal to a receiving device.
A receiving device for wireless communication may include a memory
and one or more processors operatively coupled to the memory. The
memory and the one or more processors may receive, from a
transmitting device, a non-coherent signal having at least one
segment. Each segment includes a sequence of complex symbols
corresponding to information bits and parity check bits. The
receiving device may also include jointly detecting the sequences
from each segment of the received non-coherent signal by using the
parity check bits.
A transmitting device for wireless communication may include means
for adding parity check bits to a set of information bits. The
transmitting device may also include means for generating a
non-coherent transmission signal by mapping the parity check bits
and the set of information bits into a sequence of complex symbols.
The transmitting device may also include means for transmitting the
non-coherent transmission signal to a receiving device.
A receiving device for wireless communication may include means for
receiving, from a transmitting device, a non-coherent signal having
at least one segment. Each segment may include a sequence of
complex symbols corresponding to information bits and parity check
bits. The receiving device may also include means for jointly
detecting the sequences from each segment of the received
non-coherent signal by using the parity check bits.
A non-transitory computer-readable medium may include program code
executed by a transmitting device. The medium may include program
code to add parity check bits to a set of information bits. The
medium may also include program code to generate a non-coherent
transmission signal by mapping the parity check bits and the set of
information bits into a sequence of complex symbols. The medium may
also include program code to transmit the non-coherent transmission
signal to a receiving device.
A non-transitory computer-readable medium may include program code
executed by a receiving device. The medium may include program code
to receive, from a transmitting device, a non-coherent signal
having at least one segment. Each segment may also include a
sequence of complex symbols corresponding to information bits and
parity check bits. The medium may also include program code to
jointly detect the sequences from each segment of the received
non-coherent signal by using the parity check bits.
The foregoing has outlined rather broadly the features and
technical advantages of examples according to the disclosure in
order that the detailed description that follows may be better
understood. Additional features and advantages will be described.
The conception and specific examples disclosed may be readily
utilized as a basis for modifying or designing other structures for
carrying out the same purposes of the present disclosure. Such
equivalent constructions do not depart from the scope of the
appended claims. Characteristics of the concepts disclosed, both
their organization and method of operation, together with
associated advantages will be better understood from the following
description when considered in connection with the accompanying
figures. Each of the figures is provided for the purposes of
illustration and description, and not as a definition of the limits
of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating an example of a wireless
communications system and an access network.
FIGS. 2A, 2B, 2C, and 2D are diagrams illustrating examples of a
first 5G/NR frame, DL channels within a 5G/NR subframe, a second
5G/NR frame, and UL channels within a 5G/NR subframe,
respectively.
FIG. 3 is a diagram illustrating an example of a base station and
user equipment (UE) in an access network.
FIG. 4 is a diagram illustrating an example of a coherent
communication system.
FIG. 5 is a diagram illustrating an example of a non-coherent
communication system, in accordance with certain aspects of the
disclosure.
FIG. 6 is a diagram illustrating an example of a transmitter
architecture for a non-coherent communication system, in accordance
with certain aspects of the disclosure.
FIG. 7A is a diagram illustrating another example of the
transmitter architecture for a non-coherent communication system,
in accordance with certain aspects of the disclosure.
FIG. 7B is a diagram illustrating another example of the
transmitter architecture for a non-coherent communication system,
in accordance with certain aspects of the disclosure.
FIG. 8 is a diagram illustrating an example of a receiver
architecture for a non-coherent communication system, in accordance
with certain aspects of the disclosure.
FIG. 9 is a call flow diagram of signaling between a receiving
device and a transmitting device, in accordance with certain
aspects of the disclosure.
FIG. 10 is a flowchart of a method of wireless communication.
FIG. 11 is a conceptual data flow diagram illustrating the data
flow between different means/components in an example
apparatus.
FIG. 12 is a diagram illustrating an example of a hardware
implementation for an apparatus employing a processing system.
FIG. 13 is a flowchart of a method of wireless communication.
FIG. 14 is a conceptual data flow diagram illustrating the data
flow between different means/components in an example
apparatus.
FIG. 15 is a diagram illustrating an example of a hardware
implementation for an apparatus employing a processing system.
FIG. 16 is a diagram illustrating another example of a transmitter
architecture for a non-coherent communication system, in accordance
with certain aspects of the disclosure.
FIG. 17 is a diagram illustrating an example of inserting parity
check bits for the transmitter architecture of FIG. 16, in
accordance with certain aspects of the disclosure.
FIG. 18 is a flowchart of a method of wireless communication, for
example, for a transmitting device, in accordance with various
aspects of the present invention.
FIG. 19A is a diagram illustrating an example of a transmitter
architecture for a non-coherent communication system, in accordance
with certain aspects of the disclosure.
FIG. 19B is a diagram illustrating an example of a receiver
architecture for a non-coherent communication system, in accordance
with certain aspects of the disclosure.
FIG. 20 is a flowchart of a method of wireless communication, for
example, for a receiving device, in accordance with various aspects
of the present invention.
DETAILED DESCRIPTION
Coherent communication systems may not perform well with signals
having a low signal-to-noise ratio (SNR). For example, at low SNR,
a receiver increases an amount of energy allocated for pilot
signals (e.g., a demodulation reference signal (DMRS))
transmissions to improve channel estimates. The pilot signal does
not convey any useful information, such that the energy expended to
transmit the pilot signal does not send any useful information. In
addition, the quality of channel estimates may be poor at low SNR.
If the receiver is unable to estimate the channel accurately, then
the demodulation and decoding will suffer, which may lead to
performance loss.
A UE at a cell edge may be operating at low SNR. The coherent
communication scheme utilizing the pilot may not work effectively
for such cell edge UEs. In order to overcome the issue or improve
the performance, for example at low SNR, the present disclosure
provides a non-coherent communication system.
In a coherent communication system, the receiver performs the
demodulation and decoding in a coherent manner, where the receiver
estimates the channel of the received signal based on the pilot. In
a non-coherent communication system, the transmitter does not
transmit any pilot, such as a DMRS, but instead will transmit the
information directly to the receiver. The receiver then determines
or decodes the information received from the transmitter without
performing any channel estimation. Although the receiver does not
perform any channel estimation explicitly, after the receiver
demodulates or decodes the information, a channel estimate may be a
by-product of the receiving algorithm. In other words, after the
receiver decodes and demodulates the signal, the receiver may
obtain an estimate of channel coefficients.
According to aspects of the present disclosure, parity check bits
are inserted into an information payload prior to partitioning the
information payload into groups and mapping the groups to sequences
for transmitting to a receiver. The parity bits enable the receiver
to jointly detect the groups of the information payload. The parity
bits may be cyclic redundancy check (CRC) bits. In another option,
the parity bits may be CRC bits plus additional parity check bits.
The receiver may determine a list of candidates for each group in
the received signal. The receiver selects a candidate for each
group that satisfies the parity checks.
Various aspects of the disclosure are described more fully below
with reference to the accompanying drawings. This disclosure may,
however, be embodied in many different forms and should not be
construed as limited to any specific structure or function
presented throughout this disclosure. Rather, these aspects are
provided so that this disclosure will be thorough and complete, and
will fully convey the scope of the disclosure to those skilled in
the art. Based on the teachings, one skilled in the art should
appreciate that the scope of the disclosure is intended to cover
any aspect of the disclosure disclosed, whether implemented
independently of or combined with any other aspect of the
disclosure. For example, an apparatus may be implemented or a
method may be practiced using any number of the aspects set forth.
In addition, the scope of the disclosure is intended to cover such
an apparatus or method, which is practiced using other structure,
functionality, or structure and functionality in addition to or
other than the various aspects of the disclosure set forth. It
should be understood that any aspect of the disclosure disclosed
may be embodied by one or more elements of a claim.
Several aspects of telecommunication systems will now be presented
with reference to various apparatus and methods. These apparatus
and methods will be described in the following detailed description
and illustrated in the accompanying drawings by various blocks,
components, circuits, processes, algorithms, etc. (collectively
referred to as "elements"). These elements may be implemented using
electronic hardware, computer software, or any combination thereof.
Whether such elements are implemented as hardware or software
depends upon the particular application and design constraints
imposed on the overall system.
By way of example, an element, or any portion of an element, or any
combination of elements may be implemented as a "processing system"
that includes one or more processors. Examples of processors
include microprocessors, microcontrollers, graphics processing
units (GPUs), central processing units (CPUs), application
processors, digital signal processors (DSPs), reduced instruction
set computing (RISC) processors, systems on a chip (SoC), baseband
processors, field programmable gate arrays (FPGAs), programmable
logic devices (PLDs), state machines, gated logic, discrete
hardware circuits, and other suitable hardware configured to
perform the various functionality described throughout this
disclosure. One or more processors in the processing system may
execute software. Software shall be construed broadly to mean
instructions, instruction sets, code, code segments, program code,
programs, subprograms, software components, applications, software
applications, software packages, routines, subroutines, objects,
executables, threads of execution, procedures, functions, etc.,
whether referred to as software, firmware, middleware, microcode,
hardware description language, or otherwise.
Accordingly, in one or more example embodiments, the functions
described may be implemented in hardware, software, or any
combination thereof. If implemented in software, the functions may
be stored on or encoded as one or more instructions or code on a
computer-readable medium. Computer-readable media includes computer
storage media. Storage media may be any available media that can be
accessed by a computer. By way of example, and not limitation, such
computer-readable media can comprise a random-access memory (RAM),
a read-only memory (ROM), an electrically erasable programmable ROM
(EEPROM), optical disk storage, magnetic disk storage, other
magnetic storage devices, combinations of the aforementioned types
of computer-readable media, or any other medium that can be used to
store computer executable code in the form of instructions or data
structures that can be accessed by a computer.
FIG. 1 is a diagram illustrating an example of a wireless
communications system and an access network 100. The wireless
communications system (also referred to as a wireless wide area
network (WWAN)) includes base stations 102, UEs 104, an Evolved
Packet Core (EPC) 160, and another core network 190 (e.g., a 5G
Core (5GC)). The base stations 102 may include macrocells (high
power cellular base station) and/or small cells (low power cellular
base station). The macrocells include base stations. The small
cells include femtocells, picocells, and microcells.
The base stations 102 configured for 4G LTE (collectively referred
to as Evolved Universal Mobile Telecommunications System (UMTS)
Terrestrial Radio Access Network (E-UTRAN)) may interface with the
EPC 160 through backhaul links 132 (e.g., S1 interface). The base
stations 102 configured for 5G NR (collectively referred to as Next
Generation RAN (NG-RAN)) may interface with core network 190
through backhaul links 184. In addition to other functions, the
base stations 102 may perform one or more of the following
functions: transfer of user data, radio channel ciphering and
deciphering, integrity protection, header compression, mobility
control functions (e.g., handover, dual connectivity), inter-cell
interference coordination, connection setup and release, load
balancing, distribution for non-access stratum (NAS) messages, NAS
node selection, synchronization, radio access network (RAN)
sharing, multimedia broadcast multicast service (MBMS), subscriber
and equipment trace, RAN information management (RIM), paging,
positioning, and delivery of warning messages. The base stations
102 may communicate directly or indirectly (e.g., through the EPC
160 or core network 190) with each other over backhaul links 134
(e.g., X2 interface). The backhaul links 134 may be wired or
wireless.
The base stations 102 may wirelessly communicate with the UEs 104.
Each of the base stations 102 may provide communication coverage
for a respective geographic coverage area 110. There may be
overlapping geographic coverage areas 110. For example, the small
cell 102' may have a coverage area 110' that overlaps the coverage
area 110 of one or more macro base stations 102. A network that
includes both small cell and macrocells may be known as a
heterogeneous network. A heterogeneous network may also include
Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a
restricted group known as a closed subscriber group (CSG). The
communication links 120 between the base stations 102 and the UEs
104 may include uplink (UL) (also referred to as reverse link)
transmissions from a UE 104 to a base station 102 and/or downlink
(DL) (also referred to as forward link) transmissions from a base
station 102 to a UE 104. The communication links 120 may use
multiple-input and multiple-output (MIMO) antenna technology,
including spatial multiplexing, beamforming, and/or transmit
diversity. The communication links may be through one or more
carriers. The base stations 102/UEs 104 may use spectrum up to Y
MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier
allocated in a carrier aggregation of up to a total of Yx MHz (x
component carriers) used for transmission in each direction. The
carriers may or may not be adjacent to each other. Allocation of
carriers may be asymmetric with respect to DL and UL (e.g., more or
fewer carriers may be allocated for DL than for UL). The component
carriers may include a primary component carrier and one or more
secondary component carriers. A primary component carrier may be
referred to as a primary cell (PCell) and a secondary component
carrier may be referred to as a secondary cell (SCell).
Certain UEs 104 may communicate with each other using
device-to-device (D2D) communication link 158. The D2D
communication link 158 may use the DL/UL WWAN spectrum. The D2D
communication link 158 may use one or more sidelink channels, such
as a physical sidelink broadcast channel (PSBCH), a physical
sidelink discovery channel (PSDCH), a physical sidelink shared
channel (PSSCH), and a physical sidelink control channel (PSCCH).
D2D communication may be through a variety of wireless D2D
communications systems, such as for example, FlashLinQ, WiMedia,
Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or
NR.
The wireless communications system may further include a Wi-Fi
access point (AP) 150 in communication with Wi-Fi stations (STAs)
152 via communication links 154 in a 5 GHz unlicensed frequency
spectrum. When communicating in an unlicensed frequency spectrum,
the STAs 152/AP 150 may perform a clear channel assessment (CCA)
prior to communicating in order to determine whether the channel is
available.
The small cell 102' may operate in a licensed and/or an unlicensed
frequency spectrum. When operating in an unlicensed frequency
spectrum, the small cell 102' may employ NR and use the same 5 GHz
unlicensed frequency spectrum as used by the Wi-Fi AP 150. The
small cell 102', employing NR in an unlicensed frequency spectrum,
may boost coverage to and/or increase capacity of the access
network.
A base station 102, whether a small cell 102' or a large cell
(e.g., macro base station), may include an eNB, gNodeB (gNB), or
another type of base station. Some base stations, such as gNB 180
may operate in a traditional sub 6 GHz spectrum, in millimeter wave
(mmW) frequencies, and/or near mmW frequencies in communication
with the UE 104. When the gNB 180 operates in mmW or near mmW
frequencies, the gNB 180 may be referred to as an mmW base station.
Extremely high frequency (EHF) is part of the radio frequency (RF)
in the electromagnetic spectrum. EHF has a range of 30 GHz to 300
GHz and a wavelength between 1 millimeter and 10 millimeters. Radio
waves in the band may be referred to as a millimeter wave. Near mmW
may extend down to a frequency of 3 GHz with a wavelength of 100
millimeters. The super high frequency (SHF) band extends between 3
GHz and 30 GHz, also referred to as centimeter wave. Communications
using the mmW/near mmW radio frequency band (e.g., 3 GHz-300 GHz)
has extremely high path loss and a short range. The mmW base
station 180 may utilize beamforming 182 with the UE 104 to
compensate for the extremely high path loss and short range.
The base station 180 may transmit a beamformed signal to the UE 104
in one or more transmit directions 182'. The UE 104 may receive the
beamformed signal from the base station 180 in one or more receive
directions 182''. The UE 104 may also transmit a beamformed signal
to the base station 180 in one or more transmit directions. The
base station 180 may receive the beamformed signal from the UE 104
in one or more receive directions. The base station 180/UE 104 may
perform beam training to determine the best receive and transmit
directions for each of the base station 180/UE 104. The transmit
and receive directions for the base station 180 may or may not be
the same. The transmit and receive directions for the UE 104 may or
may not be the same.
The EPC 160 may include a Mobility Management Entity (MME) 162,
other MMES 164, a Serving Gateway 166, a Multimedia Broadcast
Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service
Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172.
The MME 162 may be in communication with a Home Subscriber Server
(HSS) 174. The MME 162 is the control node that processes the
signaling between the UEs 104 and the EPC 160. Generally, the MME
162 provides bearer and connection management. All user Internet
protocol (IP) packets are transferred through the Serving Gateway
166, which itself is connected to the PDN Gateway 172. The PDN
Gateway 172 provides UE IP address allocation as well as other
functions. The PDN Gateway 172 and the BM-SC 170 are connected to
the IP Services 176. The IP Services 176 may include the Internet,
an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming
Service, and/or other IP services. The BM-SC 170 may provide
functions for MBMS user service provisioning and delivery. The
BM-SC 170 may serve as an entry point for content provider MBMS
transmission, may be used to authorize and initiate MBMS Bearer
Services within a public land mobile network (PLMN), and may be
used to schedule MBMS transmissions. The MBMS Gateway 168 may be
used to distribute MBMS traffic to the base stations 102 belonging
to a Multicast Broadcast Single Frequency Network (MBSFN) area
broadcasting a particular service, and may be responsible for
session management (start/stop) and for collecting eMBMS related
charging information.
The core network 190 may include an Access and Mobility Management
Function (AMF) 192, other AMFs 193, a Session Management Function
(SMF) 194, and a User Plane Function (UPF) 195. The AMF 192 may be
in communication with a Unified Data Management (UDM) 196. The AMF
192 is the control node that processes the signaling between the
UEs 104 and the core network 190. Generally, the AMF 192 provides
quality of service (QoS) flow and session management. All user
Internet protocol (IP) packets are transferred through the UPF 195.
The UPF 195 provides UE IP address allocation as well as other
functions. The UPF 195 is connected to the IP Services 197. The IP
Services 197 may include the Internet, an intranet, an IP
Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP
services.
The base station may also be referred to as a gNB, Node B, evolved
Node B (eNB), an access point, a base transceiver station, a radio
base station, a radio transceiver, a transceiver function, a basic
service set (BSS), an extended service set (ESS), a transmit and
reception point (TRP), or some other suitable terminology. The base
station 102 provides an access point to the EPC 160 or core network
190 for a UE 104. Examples of UEs 104 include a cellular phone, a
smart phone, a session initiation protocol (SIP) phone, a laptop, a
personal digital assistant (PDA), a satellite radio, a global
positioning system, a multimedia device, a video device, a digital
audio player (e.g., MP3 player), a camera, a game console, a
tablet, a smart device, a wearable device, a vehicle, an electric
meter, a gas pump, a large or small kitchen appliance, a healthcare
device, an implant, a sensor/actuator, a display, or any other
similar functioning device. Some of the UEs 104 may be referred to
as IoT devices (e.g., parking meter, gas pump, toaster, vehicles,
heart monitor, etc.). The UE 104 may also be referred to as a
station, a mobile station, a subscriber station, a mobile unit, a
subscriber unit, a wireless unit, a remote unit, a mobile device, a
wireless device, a wireless communications device, a remote device,
a mobile subscriber station, an access terminal, a mobile terminal,
a wireless terminal, a remote terminal, a handset, a user agent, a
mobile client, a client, or some other suitable terminology.
Although the following description may be focused on 5G NR, the
concepts described may be applicable to other similar areas, such
as LTE, LTE-A, CDMA, GSM, and other wireless technologies.
FIG. 2A is a diagram 200 illustrating an example of a first
subframe within a 5G/NR frame structure. FIG. 2B is a diagram 230
illustrating an example of DL channels within a 5G/NR subframe.
FIG. 2C is a diagram 250 illustrating an example of a second
subframe within a 5G/NR frame structure. FIG. 2D is a diagram 280
illustrating an example of UL channels within a 5G/NR subframe. The
5G/NR frame structure may be frequency division duplex (FDD) in
which for a particular set of subcarriers (carrier system
bandwidth), subframes within the set of subcarriers are dedicated
for either DL or UL, or may be time division duplex (TDD) in which
for a particular set of subcarriers (carrier system bandwidth),
subframes within the set of subcarriers are dedicated for both DL
and UL. In the examples provided by FIGS. 2A, 2C, the 5G/NR frame
structure is assumed to be TDD, with subframe 4 being configured
with slot format 28 (with mostly DL), where D is DL, U is UL, and X
is flexible for use between DL/UL, and subframe 3 being configured
with slot format 34 (with mostly UL). While subframes 3, 4 are
shown with slot formats 34, 28, respectively, any particular
subframe may be configured with any of the various available slot
formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other
slot formats 2-61 include a mix of DL, UL, and flexible symbols.
UEs are configured with the slot format (dynamically through DL
control information (DCI), or semi-statically/statically through
radio resource control (RRC) signaling) through a received slot
format indicator (SFI). Note that the description infra applies
also to a 5G/NR frame structure that is TDD.
Other wireless communication technologies may have a different
frame structure and/or different channels. A frame (10 ms) may be
divided into 10 equally sized subframes (1 ms). Each subframe may
include one or more time slots. Subframes may also include
mini-slots, which may include 7, 4, or 2 symbols. Each slot may
include 7 or 14 symbols, depending on the slot configuration. For
slot configuration 0, each slot may include 14 symbols, and for
slot configuration 1, each slot may include 7 symbols. The symbols
on DL may be cyclic prefix (CP) orthogonal frequency division
multiplexing (OFDM) (CP-OFDM) symbols. The symbols on UL may be
CP-OFDM symbols (for high throughput scenarios) or discrete Fourier
transform (DFT) spread OFDM (DFT-S-OFDM) symbols (also referred to
as single carrier frequency-division multiple access (SC-FDMA)
symbols) (for power limited scenarios; limited to a single stream
transmission). The number of slots within a subframe is based on
the slot configuration and the numerology. For slot configuration
0, different numerologies .mu. 0 to 5 allow for 1, 2, 4, 8, 16, and
32 slots, respectively, per subframe. For slot configuration 1,
different numerologies 0 to 2 allow for 2, 4, and 8 slots,
respectively, per subframe. Accordingly, for slot configuration 0
and numerology .mu., there are 14 symbols/slot and 2.sup..mu.
slots/subframe. The subcarrier spacing and symbol length/duration
are a function of the numerology. The subcarrier spacing may be
equal to 2.sup..mu.*15 kKz, where .mu. is the numerology 0 to 5. As
such, the numerology .mu.=0 has a subcarrier spacing of 15 kHz and
the numerology .mu.=5 has a subcarrier spacing of 480 kHz. The
symbol length/duration is inversely related to the subcarrier
spacing. FIGS. 2A-2D provide an example of slot configuration 0
with 14 symbols per slot and numerology .mu.=0 with 1 slot per
subframe. The subcarrier spacing is 15 kHz and symbol duration is
approximately 66.7 .mu.s.
A resource grid may be used to represent the frame structure. Each
time slot includes a resource block (RB) (also referred to as
physical RBs (PRBs)) that extends 12 consecutive subcarriers. The
resource grid is divided into multiple resource elements (REs). The
number of bits carried by each RE depends on the modulation
scheme.
As illustrated in FIG. 2A, some of the REs carry reference (pilot)
signals (RS) for the UE. The RS may include demodulation RS (DM-RS)
(indicated as R.sub.x for one particular configuration, where 100x
is the port number, but other DM-RS configurations are possible)
and channel state information reference signals (CSI-RS) for
channel estimation at the UE. The RS may also include beam
measurement RS (BRS), beam refinement RS (BRRS), and phase tracking
RS (PT-RS).
FIG. 2B illustrates an example of various DL channels within a
subframe of a frame. The physical downlink control channel (PDCCH)
carries DCI within one or more control channel elements (CCEs),
each CCE including nine RE groups (REGs), each REG including four
consecutive REs in an OFDM symbol. A primary synchronization signal
(PSS) may be within symbol 2 of particular subframes of a frame.
The PSS is used by a UE 104 to determine subframe/symbol timing and
a physical layer identity. A secondary synchronization signal (SSS)
may be within symbol 4 of particular subframes of a frame. The SSS
is used by a UE to determine a physical layer cell identity group
number and radio frame timing. Based on the physical layer identity
and the physical layer cell identity group number, the UE can
determine a physical cell identifier (PCI). Based on the PCI, the
UE can determine the locations of the aforementioned DM-RS. The
physical broadcast channel (PBCH), which carries a master
information block (MIB), may be logically grouped with the PSS and
SSS to form a synchronization signal (SS)/PBCH block. The MIB
provides a number of RBs in the system bandwidth and a system frame
number (SFN). The physical downlink shared channel (PDSCH) carries
user data, broadcast system information not transmitted through the
PBCH such as system information blocks (SIBs), and paging
messages.
As illustrated in FIG. 2C, some of the REs carry DM-RS (indicated
as R for one particular configuration, but other DM-RS
configurations are possible) for channel estimation at the base
station. The UE may transmit DM-RS for the physical uplink control
channel (PUCCH) and DM-RS for the physical uplink shared channel
(PUSCH). The PUSCH DM-RS may be transmitted in the first one or two
symbols of the PUSCH. The PUCCH DM-RS may be transmitted in
different configurations depending on whether short or long PUCCHs
are transmitted and depending on the particular PUCCH format used.
Although not shown, the UE may transmit sounding reference signals
(SRS). The SRS may be used by a base station for channel quality
estimation to enable frequency-dependent scheduling on the UL.
FIG. 2D illustrates an example of various UL channels within a
subframe of a frame. The PUCCH may be located as indicated in one
configuration. The PUCCH carries uplink control information (UCI),
such as scheduling requests, a channel quality indicator (CQI), a
precoding matrix indicator (PMI), a rank indicator (RI), and hybrid
automatic repeat request (HARM) acknowledgement/negative
acknowledgment (ACK/NACK) feedback. The PUSCH carries data, and may
additionally be used to carry a buffer status report (BSR), a power
headroom report (PHR), and/or UCI.
FIG. 3 is a block diagram of a base station 310 in communication
with a UE 350 in an access network. In the DL, IP packets from the
EPC 160 may be provided to a controller/processor 375. The
controller/processor 375 implements layer 3 and layer 2
functionality. Layer 3 includes a radio resource control (RRC)
layer, and layer 2 includes a service data adaptation protocol
(SDAP) layer, a packet data convergence protocol (PDCP) layer, a
radio link control (RLC) layer, and a medium access control (MAC)
layer. The controller/processor 375 provides RRC layer
functionality associated with broadcasting of system information
(e.g., MIB, SIBs), RRC connection control (e.g., RRC connection
paging, RRC connection establishment, RRC connection modification,
and RRC connection release), inter radio access technology (RAT)
mobility, and measurement configuration for UE measurement
reporting; PDCP layer functionality associated with header
compression/decompression, security (ciphering, deciphering,
integrity protection, integrity verification), and handover support
functions; RLC layer functionality associated with the transfer of
upper layer packet data units (PDUs), error correction through ARQ,
concatenation, segmentation, and reassembly of RLC service data
units (SDUs), re-segmentation of RLC data PDUs, and reordering of
RLC data PDUs; and MAC layer functionality associated with mapping
between logical channels and transport channels, multiplexing of
MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs
from TBs, scheduling information reporting, error correction
through HARQ, priority handling, and logical channel
prioritization.
The transmit (TX) processor 316 and the receive (RX) processor 370
implement layer 1 functionality associated with various signal
processing functions. Layer 1, which includes a physical (PHY)
layer, may include error detection on the transport channels,
forward error correction (FEC) coding/decoding of the transport
channels, interleaving, rate matching, mapping onto physical
channels, modulation/demodulation of physical channels, and MIMO
antenna processing. The TX processor 316 handles mapping to signal
constellations based on various modulation schemes (e.g., binary
phase-shift keying (BPSK), quadrature phase-shift keying (QPSK),
M-phase-shift keying (M-PSK), M-quadrature amplitude modulation
(M-QAM)). The coded and modulated symbols may then be split into
parallel streams. Each stream may then be mapped to an OFDM
subcarrier, multiplexed with a reference signal (e.g., pilot) in
the time and/or frequency domain, and then combined together using
an Inverse Fast Fourier Transform (IFFT) to produce a physical
channel carrying a time domain OFDM symbol stream. The OFDM stream
is spatially precoded to produce multiple spatial streams. Channel
estimates from a channel estimator 374 may be used to determine the
coding and modulation scheme, as well as for spatial processing.
The channel estimate may be derived from a reference signal and/or
channel condition feedback transmitted by the UE 350. Each spatial
stream may then be provided to a different antenna 320 via a
separate transmitter 318TX. Each transmitter 318TX may modulate an
RF carrier with a respective spatial stream for transmission.
At the UE 350, each receiver 354RX receives a signal through its
respective antenna 352. Each receiver 354RX recovers information
modulated onto an RF carrier and provides the information to the
receive (RX) processor 356. The TX processor 368 and the RX
processor 356 implement layer 1 functionality associated with
various signal processing functions. The RX processor 356 may
perform spatial processing on the information to recover any
spatial streams destined for the UE 350. If multiple spatial
streams are destined for the UE 350, they may be combined by the RX
processor 356 into a single OFDM symbol stream. The RX processor
356 then converts the OFDM symbol stream from the time-domain to
the frequency domain using a Fast Fourier Transform (FFT). The
frequency domain signal comprises a separate OFDM symbol stream for
each subcarrier of the OFDM signal. The symbols on each subcarrier,
and the reference signal, are recovered and demodulated by
determining the most likely signal constellation points transmitted
by the base station 310. These soft decisions may be based on
channel estimates computed by the channel estimator 358. The soft
decisions are then decoded and deinterleaved to recover the data
and control signals that were originally transmitted by the base
station 310 on the physical channel. The data and control signals
are then provided to the controller/processor 359, which implements
layer 3 and layer 2 functionality.
The controller/processor 359 can be associated with a memory 360
that stores program codes and data. The memory 360 may be referred
to as a computer-readable medium. In the UL, the
controller/processor 359 provides demultiplexing between transport
and logical channels, packet reassembly, deciphering, header
decompression, and control signal processing to recover IP packets
from the EPC 160. The controller/processor 359 is also responsible
for error detection using an ACK and/or NACK protocol to support
HARQ operations.
Similar to the functionality described in connection with the DL
transmission by the base station 310, the controller/processor 359
provides RRC layer functionality associated with system information
(e.g., MIB, SIBS) acquisition, RRC connections, and measurement
reporting; PDCP layer functionality associated with header
compression/decompression, and security (ciphering, deciphering,
integrity protection, integrity verification); RLC layer
functionality associated with the transfer of upper layer PDUs,
error correction through ARQ, concatenation, segmentation, and
reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and
reordering of RLC data PDUs; and MAC layer functionality associated
with mapping between logical channels and transport channels,
multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from
TBs, scheduling information reporting, error correction through
HARQ, priority handling, and logical channel prioritization.
Channel estimates derived by a channel estimator 358 from a
reference signal or feedback transmitted by the base station 310
may be used by the TX processor 368 to select the appropriate
coding and modulation schemes, and to facilitate spatial
processing. The spatial streams generated by the TX processor 368
may be provided to different antenna 352 via separate transmitters
354TX. Each transmitter 354TX may modulate an RF carrier with a
respective spatial stream for transmission.
The UL transmission is processed at the base station 310 in a
manner similar to that described in connection with the receiver
function at the UE 350. Each receiver 318RX receives a signal
through its respective antenna 320. Each receiver 318RX recovers
information modulated onto an RF carrier and provides the
information to a RX processor 370.
The controller/processor 375 can be associated with a memory 376
that stores program codes and data. The memory 376 may be referred
to as a computer-readable medium. In the UL, the
controller/processor 375 provides demultiplexing between transport
and logical channels, packet reassembly, deciphering, header
decompression, control signal processing to recover IP packets from
the UE 350. IP packets from the controller/processor 375 may be
provided to the EPC 160. The controller/processor 375 is also
responsible for error detection using an ACK and/or NACK protocol
to support HARQ operations.
At least one of the TX processor 368, the RX processor 356, and the
controller/processor 359 may be configured to perform aspects in
connection with the determination component 198 or non-coherent
component 199 of FIG. 1.
At least one of the TX processor 316, the RX processor 370, and the
controller/processor 375 may be configured to perform aspects in
connection with the determination component 198 or non-coherent
component 199 of FIG. 1.
FIG. 4 is a diagram 400 illustrating an example of a coherent
communication system. In wireless systems based on coherent
communication, a transmitter generates a signal by coding and
modulating 402 the signal and transmits data 404 and pilot symbols
408 or a demodulation reference signal (DMRS) along with data. The
pilot symbols 408 may be inserted with the data 404 by an insert
pilot 406. The data 404 carries the information that the
transmitter wants to send to the receiver. The pilot symbols or
DMRS 408 does not transmit information, rather, the pilot symbols
or DMRS 408 may be used by the receiver to perform channel
estimation. The receiver uses the pilot symbols or DMRS 408 to
estimate the channel 410 and then sends the channel estimation
information 412 to the demodulator/decoder 414 in order to perform
coherent demodulation and coherent decoding.
Coherent communication systems may not perform optimally at low
signal-to-noise ratio (SNR). For example, at low SNR, in order for
the receiver to estimate the channel properly, a large amount of
energy is used to transmit the pilot symbols or DMRS. Because the
pilot/DMRS does not convey any useful information, the energy
consumed to transmit the pilot does not contribute to any useful
information. This may result in a loss of energy per bit. In
addition, the quality of channel estimation may be poor at low SNR.
If the receiver is unable to estimate the channel accurately, then
the demodulation and decoding will suffer, which may lead to a
dramatic performance loss.
A UE at a cell edge may be operating at low SNR, and the coherent
communication scheme utilizing the pilot/DMRS may not work
effectively for such cell edge UEs. In order to overcome the issue
and to improve the performance, for example at low SNR, the present
disclosure provides a non-coherent communication system.
In a coherent communication system, the receiver may be configured
to perform the demodulation and decoding in a coherent manner,
where the receiver estimates the channel of the received signal
based on the pilot/DMRS. In a non-coherent communication system,
the transmitter does not transmit any pilot/DMRS, but instead will
transmit the information directly to the receiver.
FIG. 5 is a diagram 500 illustrating an example of a non-coherent
communication system. The transmitter will generate a non-coherent
transmission signal by performing the coding/modulation 502 and
then transmit the data 504 to the receiver. The receiver then
determines or decodes the information received from the transmitter
at demodulation/decode 508 without performing a channel estimation
procedure. Although the receiver does not explicitly perform a
channel estimation, after the receiver demodulates or decodes 508,
the information the channel estimate may be determined by channel
506 as a by-product of the receiving algorithm. In other words,
after the receiver decodes and demodulates the signal, the receiver
may obtain the estimate of the channel coefficient.
FIG. 6 is a diagram 600 illustrating an example of a transmitter
architecture for a non-coherent communication system. The diagram
600 of the transmitter architecture includes channel coding 602,
bit-to-sequence mapping 604, and CP-OFDM or DFT-S-OFDM 606 waveform
generation. On the transmitter side, the transmitter first encodes
the information bits 608 at the channel coding block 602, into a
coded bit stream 610. The channel coding block 602 may include
adding an error detection code (e.g., a cyclic redundancy check
(CRC)), channel coding using low density parity check (LDPC) code,
Polar code, or other block codes, such as but not limited to
Reed-Muller code or the like, interleaving, and/or rate matching.
The adding of the error detection, channel coding, interleaving
and/or rate matching may be collectively referred to as the channel
coding block 602, which may be configured to convert uncoded
information bits into coded bits prior to modulation as channel
coding. In some aspects, the channel coding block 602 may not be
utilized if the payload size (e.g., the number of information bits)
is very small (e.g., 20 bits, 40 bits, 48 bits, or the like). In
such aspects, the transmitting device may be configured to directly
map the information bits into sequences. The transmitter may also
be configured to concatenate and/or super-position the sequences to
generate the non-coherent signal (e.g., as discussed below). In the
aspect disclosed, the listing of very small payload sizes is
provided as an example, and the disclosure is not intended to be
limited to such examples of payload sizes. Other payload sizes
greater than or less than the provided examples may allow for the
channel coding block 602 not being utilized, such that the
transmitting device may directly map the information bits into
sequences.
The transmitter then maps a subset of the sequence of bits into
sequences 612 at the bit-to-sequence mapping block 604. The
non-coherent sequence mapping may map each subset of k coded bits
into a sequence of n complex symbols. For example, if the number of
coded bits is kM, then the transmitter may partition the coded bits
into M groups with k bits in each group. The transmitter may then
map each group of k bits into a sequence of length n. In some
aspects, the sequences may be selected from a set C of sequences of
cardinality 2.sup.k. The transmitter may then concatenate the
sequences 612 together to form a transmit signal of length nM,
which is distinct in view of conventional modulation (e.g., as used
in LTE or NR) in which each tuple of coded bits may be mapped to a
single complex symbol (e.g., 2 bits in QPSK, 4 bits in 16 QAM, 6
bits in 64 QAM, etc.). For example, FIG. 6, a set of k bits
a.sub.0, . . . , a.sub.k-1, after channel coding are mapped to bits
x.sub.0, . . . x.sub.n-1 of a sequence of length n. Another set of
k bits a.sub.k . . . , a.sub.2k-1, after channel coding are mapped
to x.sub.n, . . . x.sub.2n-1. Then, the sequences are concatenated
to form a concatenated sequence x.sub.0, . . . x.sub.nM-1.
In some aspects, the bit-to-sequence mapping 604 may be configured
to map groups into two sequences based on a comparison between the
groups. For example, in instances where two k-bits groups differ in
fewer bits, then the bit-to-sequence mapping 604 may map the two
k-bits into two sequences with larger cross-correlation, e.g., (0,
0, 0, 0) in comparison with (0, 0, 0, 1). In instances where two
k-bits groups differ in more bits, then the bit-to-sequence mapping
604 may map the two k-bit groups into two sequences with smaller
cross-correlation, e.g., (0, 0, 0, 0) in comparison with (1, 1, 1,
1).
The channel coding block 602 may be configured to contain all the
coding-related procedures, such as but not limited to, CRC
insertion, channel coding, rate-matching, interleaving, and/or
scrambling.
FIG. 7A is a diagram 700 illustrating an example of a transmitter
architecture for a non-coherent communication system. In some
aspects, in order to support a larger payload size, the
transmitting device may be configured to superposition multiple
sequences together. For example, the transmitting device takes as
input the L(k-log.sub.2 L) bits, where L is a positive integer
(e.g., a power of 2), and divides or partitions the bits, at block
704, into L groups where each group is comprised of k-log.sub.2 L L
bits. In some aspects, the bits of the L groups may be comprised of
coded bits or uncoded bits (e.g., informational or information
bits). The transmitting device, in some aspects, for a group of i
{0, . . . , L-1}, may add a group identifier to each group of bits
to form L bit strings of length k. For example, the transmitting
device may add a prefix or suffix, at block 704, of log.sub.2 L
bits to the group of bits to form a k bit string a.sup.(i) (e.g.,
712, 714, 716). The transmitting device may be configured to add
the group identifier to the group of bits and is not intended to be
limited to the aspects disclosed. The transmitting device may map
(e.g., at 706, 708, 710) each bit string a.sup.(i) (e.g., 712, 714,
716) to a length-n sequence x.sup.(i) (e.g., 718, 720, 722). The
transmitting device may then super-position the L sequences to
generate one length-n sequence y.sub.l 724, based as follows:
.di-elect cons..times..times. ##EQU00001##
FIG. 7B is a diagram 750 illustrating another example of a
transmitter architecture for a non-coherent communication system.
In some aspects, the transmitter device may be configured to map
the different groups of bits into sequences using different sets of
sequences. For example, block 754 may receive Lk bits 752 and
divide or partition the bits to form the k bit string a.sup.(i)
(e.g., 762, 764, 766). However, block 754 does not add a group
identifier to each group of bits, as discussed above in the example
of FIG. 7A. Instead, the transmitting device may be configured to
map the different groups of bits into sequences using different
sets of sequences, respectively (e.g., at 756, 758, 760). The
transmitting device may map (e.g., at 756, 758, 760) each bit
string a.sup.(i) (e.g., 762, 764, 766) to a length-n sequence
x.sup.(i) (e.g., 768, 770, 772). For example, a first group of bits
a.sub.0.sup.(0), . . . , a.sub.k-1.sup.(0) may be mapped to
x.sub.0.sup.(0), . . . , x.sub.n-1.sup.(0) using sequences from
sequence set C.sup.(0). A second group of bits a.sub.0.sup.(2), . .
. , a.sub.k-1.sup.(2) may be mapped to x.sub.0.sup.(2), . . . ,
x.sub.n-1.sup.(2) using sequences from sequence set C.sup.(2). An
Lth group of bits a.sub.0.sup.(L-1), . . . , a.sub.k-1.sup.(L-1)
may be mapped to x.sub.0.sup.(L-1), . . . , x.sub.n-1.sup.(L-1)
using sequences from sequence set C.sup.(L-1). In such aspects, the
group identifier may be implicitly conveyed through the sequence
set. The transmitting device may then super-position the L
sequences to generate one length-n sequence y.sub.l 774 in a manner
similar to the sequence y.sub.l 724, discussed above.
FIG. 8 is a diagram 800 illustrating an example of a receiver
architecture for a non-coherent communication system. The diagram
800 of the receiver architecture includes an OFDM/DFT-S-OFDM
demodulation block 804, a non-coherent soft demodulation block 806,
and a channel decoding block 808. For each signal y C.sup.n
received on each receive antenna, the receiving device may first
partition the received signals into M sub-groups of length n. Each
group of received signals may correspond to one sequence. In some
aspects, each group of received signals may correspond to L
super-positioned sequences. In some aspects, for example when
super-positioning does not occur, the receiver may determine a
score s.sub.j for each candidate sequence in the set C of 2.sup.k
sequences. The score s.sub.j for a candidate sequence c.sub.j may
be based on a cross-correlation between the received signal y and
the candidate sequence c.sub.j. The receiving device, using the
scores s.sub.j, may determine a log-likelihood ratio (LLR) for each
of the k bits. In some aspects, the receiving device may compute
the LLR of a particular bit as follows:
LLR(a.sub.i)=2.sup.1-k(.SIGMA..sub.j:the i th bit of c.sub.j
.sub.is 0s.sub.j-.SIGMA..sub.j:the i th bit of c.sub.j .sub.is
1s.sub.j)
The j: the i-th bit of c.sub.j is 0 refers to the sum over all
sequences with the index j, where the i-th bit of the sequence cj
is equal to 0. For example, in an aspect where k=3 and i=0, then
the sequences corresponding to the following bits are such that the
i-th bit is zero, as shown below.
TABLE-US-00001 000 001 010 011
In another example, where k=3 and i=1, then the sequences that
correspond to the following bit strings have the i-th bit equal to
1, as shown below.
TABLE-US-00002 100 101 110 111
Therefore, in this example, the LLR may be based on a difference
between a sum of scores for a particular bit to have a value of 0
and the sum of scores for the particular bit to have a value or
1.
In some aspects, the receiving device may compute the LLR of a
particular bit as follows: LLR(a.sub.i)=max{s.sub.j:j: the i th bit
of c.sub.j is 0}-max{s.sub.j:j: the i th bit of c.sub.j is 1} where
max{s.sub.j:j: the i th bit of c.sub.j is 0} represents where the
score values s.sub.1 of the i-th bit of c.sub.j is equal to 0, and
then compute the maximum of all of the score values to determine
the first term in the equation, and where max{s.sub.j:j: the i th
bit of c.sub.j is 1} represents where the score values s.sub.j of
the i-th bit of c.sub.j is equal to 1, and then compute the minimum
of all of the score values to determine the second term in the
equation.
Therefore, in this example, the LLR may be based on a difference
between a maximum score for a particular bit to have a value of 0
and a maximum score for the particular bit to have a value of
1.
FIG. 9 illustrates an example communication flow 900 between a
receiving device 902 and a transmitting device 904. The receiving
device 902 may correspond to a UE, and the transmitting device 904
may correspond to a base station. For example, in the context of
FIG. 1, the transmitting device 904 may correspond to base station
102/180 and, accordingly, the cell may include a geographic
coverage area 110 in which communication coverage is provided
and/or small cell 102' having a coverage area 110'. Further, the
receiving device 902 may correspond to at least UE 104. In another
example, in the context of FIG. 3, the transmitting device 904 may
correspond to the base station 310 and the receiving device 902 may
correspond to the UE 350. In yet other aspects, the receiving
device 902 may correspond to a base station that the transmitting
device 904 may correspond to a UE.
At block 906, the transmitting device 904 may generate a
non-coherent transmission signal including mapping a subset of bits
into a sequence of complex symbols. In some aspects, the subset of
bits may comprise a subset of coded bits. The coded bits may be
generated from a LDPC code or a Polar code. In some aspects, to
generate the non-coherent transmission signal, the transmitting
device 904 may map one or more subset of coded bits into a
respective sequence of complex symbols. Each group may be mapped
into a respective sequence of a length n of multiple sequences. The
multiple sequences may be concatenated to form the non-coherent
transmission signal. In some aspects, if two k bits group differ in
fewer bits, then the two k bit groups may be mapped into two
sequences having a larger cross-correlation. In some aspects, if
two k bits group differ in more bits, then the two k bit groups may
be mapped into two sequences having a smaller
cross-correlation.
In some aspects, to generate the non-coherent transmission signal,
the transmitting device 904 may add identification information to
each of M groups of bits to form M bit strings. The subset of bits
may be partitioned into groups. In some aspects, to add
identification information, the transmitting device 904 may reserve
one or more of the k bits to include the identification
information. In some aspects, to add identification information,
the transmitting device 904 may add a prefix or suffix comprising
the identification information to each of the M groups of bits to
form the M bit strings. In some aspects, to generate the
non-coherent transmission signal, the transmitting device 904 may
map each of the M bit strings to the respective sequence of the
length n. In some aspects, to generate the non-coherent
transmission signal, the transmitting device 904 may super-position
each of the respective sequences of the length n to generate a
super-positioned sequence of length n. The identification
information may indicate an identity of each of the groups from the
M groups involved in the super-position of the sequences.
Upon generating the non-coherent transmission signal, the
transmitting device 904 may transmit the non-coherent transmission
signal 908 to a receiving device 902. The receiving device 902
receives, from the transmitting device 904, the non-coherent
transmission signal 908 having data.
At block 910, the receiving device 902 may determine data from the
received signal 908 without performing a channel estimation.
In some aspects, for example at block 912, the receiving device 902
may perform an OFDM demodulation of the received signal. The
receiving device 902 may perform the OFDM demodulation to determine
the data from the received signal. In some aspects, the receiving
device 902 may perform the OFDM demodulation prior to performing
the non-coherent soft demodulation.
In some aspects, for example at block 914, the receiving device 902
may perform a non-coherent soft demodulation of the received
signal. The receiving device 902 may perform the non-coherent soft
demodulation in order to determine the data from the received
signal. In some aspects, the receiving device 902 may determine a
log-likelihood ratio (LLR) for each bit of the received signal. In
some aspects, to perform the non-coherent soft demodulation, the
receiving device 902 may partition the received signal into M
subgroups of length n. Each group of the received signal may
correspond to a candidate sequence. The receiving device 902 may
determine a score s.sub.j for each candidate sequence, when
performing the non-coherent soft demodulation. In some aspects, the
LLR for a bit may be based on a first sum of scores for the bit
being based on a first value minus a second sum for the bit being a
second value. In some aspects, the LLR for a bit may be based on a
first maximum score for the bit being based on a first value minus
a second maximum score for the bit being a second value. In some
aspects, the score may be based on a cross-correlation between the
received signal and the candidate sequence.
In some aspects, for example at block 916, the receiving device 902
may perform a channel decoding of the received signal. The
receiving device 902 may perform the channel decoding to determine
the data from the received signal. In some aspects, the receiving
device 902 may perform the channel decoding after performing the
non-coherent soft demodulation of the received signal. In some
aspects, an output of the channel decoding may be submitted back to
the non-coherent soft demodulation to perform an iterative
demodulation and decoding procedure, as described in 808 of FIG.
8.
FIG. 10 is a flowchart of a method 1000 of wireless communication.
The method may be performed by a receiving device (e.g., the
receiving device 902; the apparatus 1102/1102'; the processing
system 1214). The method may be performed by a transmitting device
(e.g., the transmitting device 904; the apparatus 1402/1402'; the
processing system 1514). In some aspects, the receiving device may
comprise a UE or a component of the UE, such that the method may be
performed by the UE or the component of a UE (e.g., the UE 104,
350; the apparatus 1102/1102'; the processing system 1214, which
may include the memory 360 and which may be the entire UE 350 or a
component of the UE 350, such as the TX processor 368, the RX
processor 356, and/or the controller/processor 359). In some
aspects, the receiving device may comprise a base station or a
component of the base station, such that the method may be
performed by the base station or a component of the base station
(e.g., the base station 102, 180, 310; the apparatus 1402/1402';
the processing system 1214, which may include the memory 376 and
which may be the entire base station 310 or a component of the base
station 310, such as the TX processor 316, the RX processor 370,
and/or the controller/processor 375). According to various aspects,
one or more of the illustrated operations of method 1000 may be
omitted, transposed, and/or contemporaneously performed. Optional
aspects are illustrated with a dashed line. The method may allow a
receiving device (e.g., UE or base station) to operate in a
non-coherent communication scheme and determine the information
from a received signal without performing channel estimation.
At block 1002, the receiving device may receive a non-coherent
signal having data. For example, block 1002 may be performed by
non-coherent component 1106 of apparatus 1102. The receiving device
may receive the non-coherent signal from a transmitting device. In
some aspects, the receiving device may be a UE and the transmitting
device may be a base station. In some aspects, the receiving device
may be a base station and the transmitting device may be a UE.
At block 1004, the receiving device may determine data from the
received signal without performing a channel estimation. For
example, block 1004 may be performed by determination component
1108 of apparatus 1102.
In some aspects, for example at block 1006, the receiving device
may performing an OFDM demodulation of the received signal. For
example, block 1006 may be performed by OFDM demodulation component
1110 of apparatus 1102. The receiving device may perform the OFDM
demodulation of the received signal to determine the data from the
received signal. In some aspects, the receiving device may perform
the OFDM demodulation of the received signal prior to performing
the non-coherent soft demodulation.
In some aspects, for example at block 1008, the receiving device
may perform a non-coherent soft demodulation of the received
signal. For example, block 1008 may be performed by soft
demodulation component 1112 of apparatus 1102. The receiving device
may perform the non-coherent soft demodulation of the received
signal to determine the data from the received signal.
In some aspects, for example at block 1010, the receiving device
may determine a LLR for each bit of the received signal. For
example, block 1010 may be performed by LLR component 1114 of
apparatus 1102. The receiving device may determine the LLR for each
bit of the received signal to perform the non-coherent soft
demodulation of the received signal.
In some aspects, for example at block 1012, to perform the
non-coherent soft demodulation, the receiving device may partition
the received signal into M subgroups of length n. For example,
block 1012 may be performed by partition component 1116 of
apparatus 1102. In some aspects, each group of the received signal
may correspond to a candidate sequence.
In some aspects, for example at block 1014, to perform the
non-coherent soft demodulation, the receiving device may determine
a score s.sub.j for each candidate sequence. For example, block
1014 may be performed by score component 1118 of apparatus 1102. In
some aspects, the LLR for a bit may be based on a first sum of
scores for the bit being a first value minus a second sum for the
bit being a second value. In some aspects, the LLR for a bit may be
based on a first maximum score for the bit being a first value
minus a second maximum score for the bit being a second value. In
some aspects, the score may be based on a cross-correlation between
the received signal and the candidate sequence.
In some aspects, for example at block 1016, the receiving device
may perform a channel decoding of the received signal. For example,
block 1016 may be performed by channel decoding component 1120 of
apparatus 1102. In some aspects, the receiving device may perform
the channel decoding after performing the non-coherent soft
demodulation of the received signal. In some aspects, an output of
the channel decoding may be submitted back to the non-coherent soft
demodulation in order to perform an iterative demodulation and
decoding procedure.
FIG. 11 is a conceptual data flow diagram 1100 illustrating the
data flow between different means/components in an example
apparatus 1102. The apparatus may be a receiving device. In some
aspects, the apparatus may comprise UE or a component of the UE. In
some aspects, the apparatus may comprise a base station or a
component of a base station. The apparatus includes a reception
component 1104 that may be configured to receive various types of
signals/messages and/or other information from other device,
including, for example, the transmitting device 1150. The apparatus
includes a non-coherent component 1106 that may receive a
non-coherent signal having data, e.g., as described in connection
with 1002 of FIG. 10. The apparatus includes a determination
component 1108 that may determine data from the received signal
without performing a channel estimation, e.g., as described in
connection with 1004 of FIG. 10. The apparatus includes a soft
demodulation component 1110 that may perform a non-coherent soft
demodulation of the received signal, e.g., as described in
connection with 1006 of FIG. 10. The apparatus includes an OFDM
demodulation component 1112 that may perform an OFDM demodulation
of the received signal, e.g., as described in connection with 1008
of FIG. 10. The apparatus includes an LLR component 1114 that may
determine a LLR for each bit of the received signal, e.g., as
described in connection with 1010 of FIG. 10. The apparatus
includes a partition component 1116 that may partition the received
signal into M subgroups of length n, e.g., as described in
connection with 1012 of FIG. 10. The apparatus includes a score
component 1118 that may determine a score s.sub.j for each
candidate sequence, e.g., as described in connection with 1014 of
FIG. 10. The apparatus includes a channel decoding component 1120
that may perform a channel decoding of the received signal, e.g.,
as described in connection with 1016 of FIG. 10. The apparatus
includes a transmission component 1122 that may be configured to
transmit various types of signals/messages and/or other information
to other devices, including, for example, the transmitting device
1150.
The apparatus may include additional components that perform each
of the blocks of the algorithm in the aforementioned flowchart of
FIG. 10. As such, each block in the aforementioned flowchart of
FIG. 10 may be performed by a component and the apparatus may
include one or more of those components. The components may be one
or more hardware components specifically configured to carry out
the stated processes/algorithm, implemented by a processor
configured to perform the stated processes/algorithm, stored within
a computer-readable medium for implementation by a processor, or
some combination thereof.
FIG. 12 is a diagram 1200 illustrating an example of a hardware
implementation for an apparatus 1102' employing a processing system
1214. The processing system 1214 may be implemented with a bus
architecture, represented generally by the bus 1224. The bus 1224
may include any number of interconnecting buses and bridges
depending on the specific application of the processing system 1214
and the overall design constraints. The bus 1224 links together
various circuits including one or more processors and/or hardware
components, represented by the processor 1204, the components 1104,
1106, 1108, 1110, 1112, 1114, 1116, 1118, 1120, 1122, and the
computer-readable medium/memory 1206. The bus 1224 may also link
various other circuits such as timing sources, peripherals, voltage
regulators, and power management circuits, which are well known in
the art, and therefore, will not be described any further.
The processing system 1214 may be coupled to a transceiver 1210.
The transceiver 1210 is coupled to one or more antennas 1220. The
transceiver 1210 provides a means for communicating with various
other apparatus over a transmission medium. The transceiver 1210
receives a signal from the one or more antennas 1220, extracts
information from the received signal, and provides the extracted
information to the processing system 1214, specifically the
reception component 1104. In addition, the transceiver 1210
receives information from the processing system 1214, specifically
the transmission component 1122, and based on the received
information, generates a signal to be applied to the one or more
antennas 1220. The processing system 1214 includes a processor 1204
coupled to a computer-readable medium/memory 1206. The processor
1204 is responsible for general processing, including the execution
of software stored on the computer-readable medium/memory 1206. The
software, when executed by the processor 1204, causes the
processing system 1214 to perform the various functions described
supra for any particular apparatus. The computer-readable
medium/memory 1206 may also be used for storing data that is
manipulated by the processor 1204 when executing software. The
processing system 1214 further includes at least one of the
components 1104, 1106, 1108, 1110, 1112, 1114, 1116, 1118, 1120,
1122. The components may be software components running in the
processor 1204, resident/stored in the computer readable
medium/memory 1206, one or more hardware components coupled to the
processor 1204, or some combination thereof. The processing system
1214 may be a component of the base station 310 and may include the
memory 376 and/or at least one of the TX processor 316, the RX
processor 370, and the controller/processor 375. Alternatively, the
processing system 1214 may be the entire base station (e.g., see
310 of FIG. 3). The processing system 1214 may be a component of
the UE 350 and may include the memory 360 and/or at least one of
the TX processor 368, the RX processor 356, and the
controller/processor 359. Alternatively, the processing system 1214
may be the entire UE (e.g., see 350 of FIG. 3).
In one configuration, the apparatus 310, 350 for wireless
communication includes means for adding parity check bits to a set
of information bits. The apparatus may also include means for
generating a non-coherent transmission signal. The apparatus may
also include means for transmitting the non-coherent transmission
signal to a receiving device. The apparatus may have means for
receiving, from a transmitting device, a non-coherent signal having
at least one segment. The apparatus may include means for receiving
a sequence of complex symbols corresponding to information bits and
parity check bits, and means for jointly detecting the sequences.
The aforementioned means may be one or more of the aforementioned
components of the apparatus 310/350 configured to perform the
functions recited by the aforementioned means.
FIG. 13 is a flowchart of a method 1300 of wireless communication.
The method may be performed by a transmitting device (e.g., the
transmitting device 904; the apparatus 1402/1402'; the processing
system 1514). The method may be performed by a receiving device
(e.g., the transmitting device 904; the apparatus 1402/1402; the
processing system 1514). In some aspects, the transmitting device
may comprise a UE or a component of the UE, such that the method
may be performed by the UE or the component of a UE (e.g., the UE
104, 350; the apparatus 1102/1102'; the processing system 1214,
which may include the memory 360 and which may be the entire UE 350
or a component of the UE 350, such as the TX processor 368, the RX
processor 356, and/or the controller/processor 359). In some
aspects, the transmitting device may comprise a base station or a
component of the base station, such that the method may be
performed by the base station or a component of the base station
(e.g., the base station 102, 180, 310; the apparatus 1402/1402';
the processing system 1214, which may include the memory 376 and
which may be the entire base station 310 or a component of the base
station 310, such as the TX processor 316, the RX processor 370,
and/or the controller/processor 375). According to various aspects,
one or more of the illustrated operations of method 1300 may be
omitted, transposed, and/or contemporaneously performed. Optional
aspects are illustrated with a dashed line. The method may allow a
transmitting device (e.g., base station or UE) to operate in a
non-coherent communication scheme and transmit a transmission
signal without transmitting any pilot signals or DMRS.
At block 1302, the transmitting device may generate a non-coherent
transmission signal. For example, 1302 may be performed by
generation component 1406 of apparatus 1402. The transmitting
device may include, in the non-coherent transmission signal,
mapping a subset of bits into a sequence of complex symbols. In
some aspects, the subset of bits may comprise a subset of coded
bits. The coded bits may be generated from a LDPC code or a Polar
code.
In some aspects, for example, at block 1304, to generate the
non-coherent transmission signal, the transmitting device may map
one or more subset of bits into a respective one or more sequences
of complex signals. For example, 1304 may be performed by map
component 1408 of apparatus 1402. In some aspects, each of the one
or more sequences comprises n complex symbols. In some aspects,
each group may be mapped into a respective sequence of a length n
of a plurality of sequences. In some aspects, the one or more
sequences may be concatenated to form the non-coherent transmission
signal. In some aspects, the mapping of the subset of bits into the
sequence of complex symbols may determine if two k bits group
differ in fewer bits, such that the two k bit groups may be mapped
into two sequences having a larger cross-correlation. While in
other aspects, the mapping of the subset of bits into the sequence
of complex symbols may determine if two k bits group differ in more
bits, such that the two k bit groups may be mapped into two
sequences having a smaller cross correlation.
In some aspects, to generate the non-coherent transmission signal,
the transmitting device may partition the one or more subset of
bits into M groups of bits to form M bit strings. The transmitting
device may map each of the M bit strings to the respective sequence
based on a respective sequence set of the length n. The
transmitting device may super-position each of the respective
sequences of the length n to generate a super-positioned sequence
of length n.
In some aspects, for example, at block 1306, to generate the
non-coherent transmission signal, the transmitting device may add
identification information to each of M groups of bits to form M
bit strings. For example, 1306 may be performed by identification
component 1410 of apparatus 1402. In some aspects, the subset of
bits may be partitioned into groups. The identification information
may indicate an identity of each of the groups from the M groups
involved in the super-position.
In some aspects, for example, at block 1308, to add the
identification information, the transmitting device may reserve one
or more k bits to include the identification information. For
example, 1308 may be performed by reservation component 1412 of
apparatus 1402.
In some aspects, for example, at block 1310, to add the
identification information, the transmitting device may add a
prefix or suffix comprising the identification information to each
of the M groups of bits to form the M bit strings. For example,
1310 may be performed by add component 1414 of apparatus 1402.
In some aspects, for example at block 1312, to generate the
non-coherent transmission signal, the transmitting device may map
each of the M bit strings to the respective sequence of the length
n. For example, 1312 may be performed by sequence component 1416 of
apparatus 1402.
In some aspects, for example at block 1314, to generate the
non-coherent transmission signal, the transmitting device may
super-position each of the respective sequences of the length n to
generate a super-positioned sequence of length n. For example, 1314
may be performed by super-position component 1418 of apparatus
1402.
At block 1316, the transmitting device may transmit the
non-coherent transmission signal to a receiving device. For
example, 1316 may be performed by non-coherent component 1420 of
apparatus 1402.
FIG. 14 is a conceptual data flow diagram 1400 illustrating the
data flow between different means/components in an example
apparatus 1402. The apparatus may be a transmitting device. In some
aspects, the apparatus may comprise a UE or a component of the UE.
In some aspects, the apparatus may comprise a base station or a
component of a base station. The apparatus includes a reception
component 1404 that may be configured to receive various types of
signals/messages and/or other information from other device,
including, for example, the receiving device 1450. The apparatus
includes a generation component 1406 that may generate a
non-coherent transmission signal, e.g., as described in connection
with 1302 of FIG. 13. The apparatus includes a map component 1408
that may map one or more subset of bits into a respective one or
more sequences, e.g., as described in connection with 1304 of FIG.
13. The apparatus includes an identification component 1410 that
may add identification information to each of M groups of bits to
form M bit strings, e.g., as described in connection with 1306 of
FIG. 13. The apparatus includes a reservation component 1412 that
may reserve one or more of the k bits to include the identification
information, e.g., as described in connection with 1308 of FIG. 13.
The apparatus includes an add component 1414 that may add a prefix
or suffix comprising the identification information to each of the
M groups of bits to form the M bit strings, e.g., as described in
connection with 1310 of FIG. 13. The apparatus includes a sequence
component 1416 that may map each of the M bit strings to the
respective sequence of the length n, e.g., as described in
connection with 1312 of FIG. 13. The apparatus includes a
super-position component 1418 that may super-position each of the
respective sequences of the length n to generate a super-positioned
sequence of length n, e.g., as described in connection with 1314 of
FIG. 13. The apparatus includes a non-coherent component 1420 that
may transmit the non-coherent transmission signal to a receiving
device, e.g., as described in connection with 1316 of FIG. 13. The
apparatus includes a transmission component 1422 that may be
configured to transmit various types of signals/messages and/or
other information to other devices, including, for example, the
receiving device 1450.
The apparatus may include additional components that perform each
of the blocks of the algorithm in the aforementioned flowchart of
FIG. 13. As such, each block in the aforementioned flowchart of
FIG. 13 may be performed by a component and the apparatus may
include one or more of those components. The components may be one
or more hardware components specifically configured to carry out
the stated processes/algorithm, implemented by a processor
configured to perform the stated processes/algorithm, stored within
a computer-readable medium for implementation by a processor, or
some combination thereof.
FIG. 15 is a diagram 1500 illustrating an example of a hardware
implementation for an apparatus 1402' employing a processing system
1514. The processing system 1514 may be implemented with a bus
architecture, represented generally by the bus 1524. The bus 1524
may include any number of interconnecting buses and bridges
depending on the specific application of the processing system 1514
and the overall design constraints. The bus 1524 links together
various circuits including one or more processors and/or hardware
components, represented by the processor 1504, the components 1404,
1406, 1408, 1410, 1412, 1414, 1416, 1418, 1420, 1422, and the
computer-readable medium/memory 1506. The bus 1524 may also link
various other circuits such as timing sources, peripherals, voltage
regulators, and power management circuits, which are well known in
the art, and therefore, will not be described any further.
The processing system 1514 may be coupled to a transceiver 1510.
The transceiver 1510 is coupled to one or more antennas 1520. The
transceiver 1510 provides a means for communicating with various
other apparatus over a transmission medium. The transceiver 1510
receives a signal from the one or more antennas 1520, extracts
information from the received signal, and provides the extracted
information to the processing system 1514, specifically the
reception component 1404. In addition, the transceiver 1510
receives information from the processing system 1514, specifically
the transmission component 1422, and based on the received
information, generates a signal to be applied to the one or more
antennas 1520. The processing system 1514 includes a processor 1504
coupled to a computer-readable medium/memory 1506. The processor
1504 is responsible for general processing, including the execution
of software stored on the computer-readable medium/memory 1506. The
software, when executed by the processor 1504, causes the
processing system 1514 to perform the various functions described
supra for any particular apparatus. The computer-readable
medium/memory 1506 may also be used for storing data that is
manipulated by the processor 1504 when executing software. The
processing system 1514 further includes at least one of the
components 1404, 1406, 1408, 1410, 1412, 1414, 1416, 1418, 1420,
1422. The components may be software components running in the
processor 1504, resident/stored in the computer readable
medium/memory 1506, one or more hardware components coupled to the
processor 1504, or some combination thereof. The processing system
1514 may be a component of the base station 310 and may include the
memory 376 and/or at least one of the TX processor 316, the RX
processor 370, and the controller/processor 375. Alternatively, the
processing system 1514 may be the entire base station (e.g., see
310 of FIG. 3). The processing system 1514 may be a component of
the UE 350 and may include the memory 360 and/or at least one of
the TX processor 368, the RX processor 356, and the
controller/processor 359. Alternatively, the processing system 1514
may be the entire UE (e.g., see 350 of FIG. 3).
When a group of information bits is segmented and mapped to
separate sequences, the reliability of the overall payload may
depend on the reliability of each segment. Thus, if any segment is
not decoded successfully, the receiver may not be able to decode
the whole payload, thereby resulting in a higher probability of a
communication error. A channel coding (such as LDPC/polar or
Reed-Muller code) component, as explained with respect to FIG. 6,
may reduce the probability of a communication error by jointly
protecting the segments of information payload. However, to fully
realize the channel coding gain using conventional channel coding
schemes, the receiver may be too complicated to implement.
According to aspects of the present disclosure, parity check bits
are inserted, instead of performing the more complicated channel
coding previously described. Together with a list decoder
(explained later), the proposed scheme will have a better tradeoff
between communication reliability and receiver complexity. Such
improvements are now described with reference to FIGS. 16-20.
FIG. 16 is a diagram illustrating another example of a transmitter
architecture for a non-coherent communication system, in accordance
with certain aspects of the disclosure. The transmitter 1600 shown
in FIG. 16 is similar to the transmitter 700 shown in FIG. 7A. The
transmitter 1600 of FIG. 16, however, inserts parity check bits to
the groups of information bits at block 1610, prior to partitioning
bits and adding the group identifier at block 704. By inserting
parity check bits, performance of the transmitter 1600 does not
decrease as a payload size increases. Although FIG. 16 shows
superpositioning of the sequences at element 1690 where
y.sub.l=.SIGMA..sub.i.di-elect cons.(0, . . . , L-1)xi.sup.(i),
l=0, . . . , n-1, concatenation is also possible where [y.sub.0, .
. . , y.sub.nL-1]=[x.sub.0.sup.(0), . . . x.sub.n-1.sup.(0), . . .
, x.sub.0.sup.(1), . . . , x.sub.n-1.sup.(1), . . . ,
x.sub.0.sup.(L-1), . . . , x.sub.n-1.sup.(L-1)], where L is the
number of sequences.
FIG. 17 is a diagram illustrating an example of inserting parity
check bits for the transmitter architecture of FIG. 16, in
accordance with certain aspects of the disclosure. In FIG. 17,
block 1710 is one example of block 1610 from FIG. 16. In FIG. 17, a
number of parity check bits, A, are inserted at block 1710. The
bits inserted are CRC bits, in this example. A number, k, of
information bits, a, are included in the information payload. That
is, the set of information bits, a, includes information bits
a.sub.0, . . . , a.sub.k-1. After processing at block 1710, the
output set, b, includes bits
.times..times..times..times..times..times..times..times.
##EQU00002##
In this case, the parameter f.sub.j denotes the j.sup.th CRC bit
with j=k-k+1. For example, when 11<k<19 bits, seven to nine
CRC bits may be used. In this example, the transmitter generates
the CRC bits from primitive polynomials in the binary field
GF(2.sup.A), in other words, the finite field of 2.sup.A elements.
For example, when A=9, either of the following two polynomials may
be used: g.sub.crc,9(D)=D.sup.9+D.sup.8+D.sup.6+D.sup.5+1 or
g.sub.crc,9(D)=D.sup.9+D.sup.5+1, where the polynomial function
g(D) represents the CRC function. Encoding by CRC may be calculated
by dividing the polynomial formed by the data payload by the CRC
polynomial g(D).
As shown in FIG. 16, a transmitter 1600 may add parity check bits
to a set of information bits (block 1610) prior to non-coherent
transmission. FIG. 17 illustrates one option of inserting CRC bits
as parity check bits. In another option, the transmitter 1600
inserts CRC bits along with additional parity check bits. In this
option, the CRC bits may be generated as defined by the current new
radio (NR) specification. Additional details of this option are
provided later in this description.
FIG. 18 is a flowchart of a method of wireless communication, for
example, for a transmitting device, in accordance with various
aspects of the present invention. FIG. 18 shows a method 1800 that
may include adding parity check bits to a set of information bits
(block 1820) prior to non-coherent transmission. The UE 350 or base
station 310 (using, for example, the controller/processor 375, 359
and memory 376, 360) inserts parity check bits into the information
payload, prior to partitioning the bits and sequence mapping.
In some aspects, the method 1800 may include generating a
non-coherent transmission signal by mapping the parity check bits
and the set of information bits into a sequence of complex symbols
(block 1840). For example, the UE 350 or base station 310 (using,
for example, the controller/processor 375, 359 and memory 376, 360)
maps the bits to sequences. Optionally, the UE can either
superposition the sequences into one length-n signal, or
concatenate the L sequences into a length n*L signal. If
concatenation occurs, a group identifier can be omitted.
In some aspects, the method 1800 may include transmitting the
non-coherent transmission signal to a receiving device (block
1860). For example, the UE 350 or base station 310, (using the
antenna 352, 320, modulator 354, 318, transmit processor 368, 316,
controller/processor 359, 375, and memory 360, 376) transmits the
signal.
The information bits may be an uplink control information (UCI)
payload transmitted on a physical uplink control channel (PUCCH).
In this case, the technique enhances cell coverage for cell edge
UEs. In this PUCCH example, the transmitter is a UE and the
receiver is a base station. Both the transmitter and the receiver
determine the number of segments, and also determine the number of
parity check bits based on the payload size. If the parity check
bits are cyclic redundancy check (CRC) bits and if the payload is
an uplink control information (UCI) payload of 11 bits or less, no
parity check bits are added and segmentation does not occur. If the
payload is between 12 and 19 bits, two segments are used, and seven
to nine CRC bits are inserted. If the number of UCI bits is greater
than or equal to 20, more than two segments are used, and 16 CRC
bits are inserted.
If the parity check bits are CRC bits plus additional parity check
bits, the additional parity check bits are based on a binary
function of the information bits and/or the CRC bits. The parity
check function should incorporate information bits/CRC bits from at
least two different groups.
According to aspects of the present disclosure, the transmitter and
the receiver both determine the number of segments, and also the
number of parity check bits based on the UCI payload size. If the
UCI payload is between 12 and 19 bits, two segments are created,
and six CRC bits and one to three additional parity check bits are
provided. The number of additional parity bits may depend on
whether there is an even or odd number of bits in the UCI payload.
If an odd number is present, one or three additional bits are
inserted. Otherwise, two additional parity check bits are provided.
Thus, in both cases, an even number of information plus party bits
results, allowing equal division into two subsets/segments. If the
number of UCI bits is 20 or more, 11 CRC bits and four additional
bits are inserted. Similar to the two segment case (k=2) discussed
above, if more than two segments exist (k>2), the number of
additional parity check bits may be determined such that the total
number of information plus parity check bits (including the CRC
bits) is a multiple of the number of segments k, allowing equal
division into k subsets/segments.
In addition to UCI transmitted over a PUCCH, for example in 5G NR
or another radio access technology (RAT), the payload may be
sidelink control information (SCI) or a feedback transmission, or a
discovery signal transmitted over a sidelink, such as an NR
sidelink, for example. The payload may also be a random access
channel (RACH) signal in 5G NR or another RAT. In still another
example, the payload may be downlink control information (DCI) or a
wake up signal.
FIG. 19A is a diagram illustrating an example of a transmitter
architecture for a non-coherent communication system, in accordance
with certain aspects of the disclosure. FIG. 19B is a diagram
illustrating an example of a receiver architecture for a
non-coherent communication system, in accordance with certain
aspects of the disclosure. The transmitter 1900 of FIG. 19A is
similar to the transmitter 1600 of FIG. 16. In the example FIG.
19A, the transmitter 1900 outputs two sequences x.sup.(0) and
x.sup.(1) that are either superpositioned (not shown) into one
length n signal or concatenated (not shown) into a length n.times.L
signal, y.sub.0, . . . , y.sub.N-1 for transmission to a receiver
1950, where L represents the number of sequences. The receiver 1950
includes a sequence detection block 1902 to process a received
signal to generate a first list of candidates for the first
sequence x.sup.(0) 1904 and a second list of candidates for the
second sequence x.sup.(1) 1906. The receiver 1950 finds a candidate
in each list that satisfies the parity checks, at block 1908, and
outputs the jointly detected first and second sequences x.sup.(0)
and x.sup.(1). Although two lists and sequences (e.g., segments)
are described, the present disclosure is not limited to two.
FIG. 20 is a flowchart of a method of wireless communication, for
example, for a receiving device, in accordance with various aspects
of the present invention. As shown in FIG. 20, in some aspects, a
method 2000 may perform non-coherent reception. The method 2000 may
include receiving, from a transmitting device, a non-coherent
signal having multiple segments. Each segment comprises a sequence
of complex symbols corresponding to information bits and parity
check bits (block 2020). For example, the receiver device 310, 350
may receive (via the antenna 320, 352, demodulator 318, 354,
receive processor 370, 356, controller/processor 375, 359, and
memory 376, 360) the non-coherent signal. The non-coherent signal
includes multiple segments. For example, if the transmitter divided
the information plus parity bits into two segments, then two
sequences form the non-coherent signal.
The goal of the receiver is to determine the two sequences. Thus,
once the signal is received, in some aspects, the receiver may
jointly detect the sequences from each segment of the received
signal by using the parity check bits (block 2040). For example,
the receiving device 310, 350 may process the data with the
controller/processor 375, 359, and memory 376, 360.
Rather than detecting the two candidate sequences separately from
the received signal, the receiver may produce two lists of
candidates for the two sequences, respectively (e.g., a first list
and a second list for the first sequence and the second sequence as
shown in FIG. 19B). The receiver may find a first detected sequence
in the first list and a second detected sequence in the second
list, such that they satisfy the parity checks (e.g., the
information plus parity bits that correspond to the two sequences
satisfy the parity check conditions). Namely, each candidate in the
first list and the second list may correspond to a set of bits. The
receiver may take a first arbitrary candidate from the first set
and a second arbitrary candidate from the second set, determine
their corresponding bits, and examine if the two sets of bits
jointly satisfy the parity checks. If so, then this pair of
sequences is assumed to be the pair transmitted by the transmitter.
If not, then the receiver may move to another pair of sequences
(e.g., one from each list) until the receiver finds a pair of
sequences with corresponding bits that satisfy the parity checks.
In other words, the receiver uses the parity check bits to
determine the final candidate from each list.
According to aspects of the present disclosure, a product of the
size of the first list and the second list should be smaller than a
threshold. For example, the threshold may be determined based on
the total parity check length (A) and a predetermined false alarm
rate, P.sub.FA. In one example, T.sub.0.times.T.sub.1 . . .
.times.T.sub.L-1.ltoreq.P.sub.FA.times.2.sup.A, where Tj denotes
the list size Tj for the j.sup.th list, P.sub.FA represents the
determined false alarm rate, and A is the total parity check
length.
The present disclosure relates to a non-coherent communication
system, where a receiving device may be configured to determine or
decode information received from a transmitting device without
performing any channel estimation. Furthermore, the transmitting
device may be configured to not transmit any pilot/DMRS, which may
provide additional resources to transmit the information to the
receiving device. At least one advantage of the disclosure is that
the non-coherent scheme may be utilized in the uplink for coverage
enhancement (e.g., PUCCH and/or PUSCH channels). At least another
advantage of the disclosure is that the non-coherent scheme may be
used for preamble-less random access in a 2-step RACH procedure.
For example, instead of transmitting preamble and data (e.g.,
message A), the transmitting device may directly transmit the data
using the non-coherent communication without transmitting a DMRS
and the preamble. Another advantage is that the non-coherent scheme
may be used on PDCCH targeting for complexity reduction, which may
reduce the complexity of blind decoding. In addition, the
non-coherent scheme may be used on a discovery channel in sidelink
communication (e.g., UE to UE communication).
Implementation examples are described in the following numbered
clauses:
1. A method of wireless communication at a transmitting device,
comprising:
adding parity check bits to a set of information bits;
generating a non-coherent transmission signal by mapping the parity
check bits and the set of information bits into a sequence of
complex symbols; and
transmitting the non-coherent transmission signal to a receiving
device.
2. The method of clause 1, in which the parity check bits comprise
cyclic redundancy check (CRC) bits.
3. The method of clause 1 or 2, in which the parity check bits
further comprise additional parity check bits based on the set of
information bits and/or the CRC bits.
4. The method of any of the preceding clauses, in which generating
the non-coherent transmission signal comprises:
segmenting the set of information bits and the parity check bits
into a plurality of segments comprising subsets of information plus
parity bits; and
mapping each subset to a respective sequence of a plurality of
sequences for the non-coherent transmission signal, each sequence
comprising n complex symbols.
5. The method of clause 4, in which the parity check bits comprise
cyclic redundancy check (CRC) bits and additional parity check bits
that are based on at least two different subsets of the set of
information plus parity bits and/or at least two different subsets
of the CRC bits. 6. The method of clause 4 or 5, in which the
plurality of sequences are concatenated to form the sequence of
complex symbols for the non-coherent transmission signal. 7. The
method of clause 4 or 5, in which the plurality of sequences are
super-positioned to form the sequence of complex symbols for the
non-coherent transmission signal. 8. The method of clause 4, 5, 6,
or 7, further comprising determining a quantity of the plurality of
segments based on a quantity of bits for a payload, in response to
the set of information bits comprising the payload. 9. The method
of clause 4, 5, 6, 7, or 8, in which the information bits comprise
an uplink control information (UCI) payload transmitted on a
physical uplink control channel (PUCCH). 10. The method of any of
the preceding clauses, in which the parity check bits comprise a
first quantity of cyclic redundancy check (CRC) bits when a payload
corresponding to the set of information bits is smaller than a
threshold and the parity check bits comprise a second quantity of
bits when the payload corresponding to the set of information bits
is greater than the threshold. 11. The method of any of the
preceding clauses, in which the parity check bits comprise a first
quantity of cyclic redundancy check (CRC) bits and a second
quantity of additional parity check bits when a payload
corresponding to the set of information bits is smaller than a
threshold, and the parity check bits comprise a third quantity of
CRC bits a fourth quantity of additional parity check bits when the
payload corresponding to the set of information bits is greater
than the threshold. 12. The method of any of the preceding clauses,
further comprising determining a quantity of parity check bits
based on a quantity of segments into which the set of information
bits are partitioned. 13. A method of wireless communication at a
receiving device, comprising:
receiving, from a transmitting device, a non-coherent signal having
at least one segment, each segment comprising a sequence of complex
symbols corresponding to information bits and parity check bits;
and
jointly detecting the sequence from each segment of the received
non-coherent signal by using the parity check bits.
14. The method of clause 13, in which the jointly detecting
comprises:
generating a list of candidates for each sequence; and
finding the sequence in each list of candidates based on the parity
check bits.
15. The method of clause 14, in which finding the sequence further
comprises finding the sequence such that corresponding information
bits and parity check bits of the sequence in each list of
candidates satisfy parity check conditions represented by the
parity check bits. 16. The method of clause 15, in which a product
of a size of each list is smaller than a threshold that is based on
a predetermined false alarm rate and a quantity of parity check
bits. 17. The method of clause 13, 14, 15, or 16, further
comprising determining a quantity of parity check bits based on a
quantity of bits for a payload in response to the information bits
comprising the payload. 18. The method of any of clauses 13-17,
further comprising determining a quantity of the at least one
segment based on a quantity of bits for a payload in response to
the information bits comprising the payload. 19. The method of any
of clauses 13-18, further comprising determining the information
bits based on jointly detecting the sequences. 20. A transmitting
device for wireless communication comprising:
a memory, and
one or more processors operatively coupled to the memory, the
memory and the one or more processors configured: to add parity
check bits to a set of information bits; to generate a non-coherent
transmission signal by mapping the parity check bits and the set of
information bits into a sequence of complex symbols; and to
transmit the non-coherent transmission signal to a receiving
device. 21. The transmitting device of clause 20, in which the
parity check bits comprise cyclic redundancy check (CRC) bits. 22.
The transmitting device of clause 21, in which the parity check
bits further comprise additional parity check bits based on the set
of information bits and/or the CRC bits. 23. The transmitting
device of any of clauses 20-22, in which the one or more processors
are further configured:
to segment the set of information bits and the parity check bits
into a plurality of segments comprising subsets of information plus
parity bits; and
to map each subset to a respective sequence of a plurality of
sequences for the non-coherent transmission signal, each sequence
comprising n complex symbols.
24. The transmitting device of clause 23, in which the parity check
bits comprise cyclic redundancy check (CRC) bits and additional
parity check bits that are based on at least two different subsets
of the set of information plus parity bits and/or at least two
different subsets of the CRC bits. 25. The transmitting device of
clause 23 or 24, in which the plurality of sequences are
concatenated to form the sequence of complex symbols to form the
non-coherent transmission signal. 26. The transmitting device of
clause 23 or 24, in which the plurality of sequences are
super-positioned to form the sequence of complex symbols to form
the non-coherent transmission signal. 27. The transmitting device
of any of clauses 20-26, in which the parity check bits comprise a
first quantity of cyclic redundancy check (CRC) bits when a payload
corresponding to the set of information bits is smaller than a
threshold and the parity check bits comprise a second quantity of
bits when the payload corresponding to the set of information bits
is greater than the threshold. 28. The transmitting device of any
of clauses 20-27, in which the parity check bits comprise a first
quantity of cyclic redundancy check (CRC) bits and a second
quantity of additional parity check bits when a payload
corresponding to the set of information bits is smaller than a
threshold, and the parity check bits comprise a third quantity of
CRC bits a fourth quantity of additional parity check bits when the
payload corresponding to the set of information bits is greater
than the threshold. 29. The transmitting device of any of clauses
20-28, in which the one or more processors are further configured
to determine a quantity of parity check bits based on a quantity of
segments into which the set of information bits are
partitioned.
It is understood that the specific order or hierarchy of blocks in
the processes/flowcharts disclosed is an illustration of example
approaches. Based upon design preferences, it is understood that
the specific order or hierarchy of blocks in the
processes/flowcharts may be rearranged. Further, some blocks may be
combined or omitted. The accompanying method claims present
elements of the various blocks in a sample order, and are not meant
to be limited to the specific order or hierarchy presented.
It will be apparent that systems and/or methods described may be
implemented in different forms of hardware, firmware, and/or a
combination of hardware and software. The actual specialized
control hardware or software code used to implement these systems
and/or methods is not limiting of the aspects. Thus, the operation
and behavior of the systems and/or methods were described without
reference to specific software code--it being understood that
software and hardware can be designed to implement the systems
and/or methods based, at least in part, on the description.
The previous description is provided to enable any person skilled
in the art to practice the various aspects described. Various
modifications to these aspects will be readily apparent to those
skilled in the art, and the generic principles defined may be
applied to other aspects. Thus, the claims are not intended to be
limited to the aspects shown, but is to be accorded the full scope
consistent with the language claims, wherein reference to an
element in the singular is not intended to mean "one and only one"
unless specifically so stated, but rather "one or more." The word
"exemplary" is used to mean "serving as an example, instance, or
illustration." Any aspect described as "exemplary" is not
necessarily to be construed as preferred or advantageous over other
aspects. Unless specifically stated otherwise, the term "some"
refers to one or more. Combinations such as "at least one of A, B,
or C," "one or more of A, B, or C," "at least one of A, B, and C,"
"one or more of A, B, and C," and "A, B, C, or any combination
thereof" include any combination of A, B, and/or C, and may include
multiples of A, multiples of B, or multiples of C. Specifically,
combinations such as "at least one of A, B, or C," "one or more of
A, B, or C," "at least one of A, B, and C," "one or more of A, B,
and C," and "A, B, C, or any combination thereof" may be A only, B
only, C only, A and B, A and C, B and C, or A and B and C, where
any such combinations may contain one or more member or members of
A, B, or C. All structural and functional equivalents to the
elements of the various aspects described throughout this
disclosure that are known or later come to be known to those of
ordinary skill in the art are expressly incorporated by reference
and are intended to be encompassed by the claims. Moreover, nothing
disclosed is intended to be dedicated to the public regardless of
whether such disclosure is explicitly recited in the claims. The
words "module," "mechanism," "element," "device," and the like may
not be a substitute for the word "means." As such, no claim element
is to be construed as a means plus function unless the element is
expressly recited using the phrase "means for."
* * * * *
References